644089463 has 2 divisors, whose sum is σ = 644089464. Its totient is φ = 644089462.

The previous prime is 644089399. The next prime is 644089469. The reversal of 644089463 is 364980446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644089463 - 2⁶ = 644089399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644089469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322044731 + 322044732.

It is an arithmetic number, because the mean of its divisors is an integer number (322044732).

Almost surely, 2^644089463 is an apocalyptic number.

644089463 is a deficient number, since it is larger than the sum of its proper divisors (1).

644089463 is an equidigital number, since it uses as much as digits as its factorization.

644089463 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 497664, while the sum is 44.

The square root of 644089463 is about 25378.9176877187. The cubic root of 644089463 is about 863.6054971770.

The spelling of 644089463 in words is "six hundred forty-four million, eighty-nine thousand, four hundred sixty-three".